Photographic camera including a scanning exposure system with compensation for cylindrical perspective distortion by optical path length changes



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BSTBAC? 0F THE BSCLSURE This disclosure depicts acompact hand-held photographic camera with a `scanning exposure system having Va folded optical path. Compensation means are disclosed b'y which the magnification of elemental images formed successively by the exposure system may be altered duringa scan of the object by varying the optical path length of expzsure light in image space.

Summary o the invention One forni o'f this invention concerns a scanning exposure system for exposing photosensitive materials in a compact photographic' camera, including image-forming means for forming an image of an object to be ph0to graplied `at a predetermined image area and scanning means cooperating with the image-forming means to elect a continuous angular opticalv sn o the object such that successively scanned object points are imaged in succession by the image-forming means. Compensation means are included for altering the magnification of successively formed elemental images by varying thc optical path length ofexposure light in image space such that the images formed are substantially free of cylindrical perspective distortion, as defined herein. it is another. aspect of this inventionthat means be provided in such a scanning exposure systemcoordinated with the scanning means for causing all parts of the said total image to be in sharp focus.

ABackground of the invention' i Traditionally, hand-held photographic cameras designed to accommodate'photosensitive materials with relatively large format hlm have been relatively bulky and cumbersome when in use because of the size of the exposure chamber which is necessary to form a relatively large photographic image with a conventional static rectilinear imaging system. The utiiization of' bellows is common for enabling cameras to be folded when not in use. Howevcrfthe necessity of erecting such folding cameras before use and the somewhat large overall dimensions of the erected camera when in use has proven to he an inconvenience. The use of -short focal length, wide angle lenses has enabled the use Ginori-folding cameras with rigid-walled exposure chambers; however, apart from being somewhat bulky.- the relatively small scale of the' image and the problems attending the use of wide angle objectives ren-tiers such cameras unsatisfactory for many photographic applications,

this invention concerns a compact camerawhich over. comes the objections set forth above, accommodating a relatively long focal length objective and a correspondingiy large format film, and yet offering a permanently eieeted-exposurefsynem in an extremely compact rigid housing. 1n order to obtain such a `compact camera, in

sa claims one form (illustrated in HGUR l) the exposure light nath folded along two mutually orthogonal aries par# allel to the length and depth dimensions of the camera.

`The camera functions by effecting a continuous angular optical .scan of the object to 'oe photographed whiie'simul.

taoeotisly imaging succsimly scanned obie pointsV through a focal-plane exposure slit upon photo'nsitive materials 'caused 'toA move behind the slit at a'velociy `which isooordirtated with the rate at which the obiecx scanne-:L l

A Ascanning exposure system, as described is subieizt to inherent aberrations of any practical lei-rs, namely, the

monochromatic (Seidel) aberrations consisting of astig-rV `matism, coma, etzval curvature (curvature of heid),

distortion, 'and spherical aberration in addition to the chromaticiahcriations. Hoevwer, such a scanning syr- V tern is also subject lo a' number of additional aberrations,

the correction of one of which, cylindrical perspective distortion (defined below), is an important part of' this invention.

Gbjects of tbe invention Accordingly, it is an object of this invention to'provide an extremely compact photographic camera having a scanning exposure system and means for varying the optical mth length of exposure light inimage space to compensate for cylindrical perspective distortion' in the images 'formed by the exposure system.

It is another object of this invention to provide a compact photographic camera having a scanning exposure system for opticallyl scanning an object to 'oe photosl lgraphecl and imaging succcssively'scanned Obie-ct points in succession at a predetermined image area such that a complete image of the object maybe recorded upon image-receiving means moved relative to the image area dur'mg a scan of the object,- the system further including compensation means coordinated -with the scanning means for altering the magnification of cle'eiental images formed successively during a scan of the object by vary ing the optical path' length of exposure light in image space such that all parts of the total image 'formed are substantially free from cylindrical perspective distortion, as defined above. i

It is a further object that such compensation means he adaptable to a scanning exposure system having an optical path folded such that it may be aommodated in an extremely compact cxposurc chamber.

it is yet another object of this invention to provide means for altering the efective focal distance during a Scan of the object of image-forming means comprising art of such la scanning' excosure s 'stem such that the p c sessir'ig the construction, combination of elements and arrangement of parts which are cxeniplilied in the t'ollovling detailed disclosure* and the scope ofthe application of which will be indicated in the clairt't's.

For a fuller understanding of the nature and obiects of the invention,v reference should be had to the follow- Y ing detailed description taken in connection with the aocompanyin g drawings. t

i Brief desorption or the dmv/ngi FIGURE. l is a schematic illustration of a-compact photographic camera`4 including a scanning exposure sys sam axis). which may imcrml Thus, the. spit-ted scanning cxposur'c system' my.' hrtvc nn cxposmc chamber sitos@ dimcnnion in Ll'e direction cori-:spending o tb: I-X nxi is very substantially than the corresQoncling4 dimension in thc czcpaaurc clmmbcr g employing a static rcctlinr systcrn o corresponding ioctl length ann" nlm format sizc.

Trtnsort mcfms 34 arc provided lortmnsportng thc Dbotomnsitivt: materials 3l behind thc exposure slit 32 .duri g :ui cxpcvsurc inter-ml at t velocity whictt is cioscly coordinated 'with the avec? ntic of thc scanning mirror Cnrcul corrclztzion mctwccn thc film tnttsport velocity :and thc @ctn mtr: is occa. ry in orticr that succccaivsly ztsannccl object points :lrc'irttngincd in the corrcct :tdi^nt relationship on IlvcptOtoscrmitive materials 3l to tous: thc imzigfc formed on thc ,'inotoncnftitivc materials 3l. to 'tvc aubtnrtzitlly stutionary with rc5;:ct tllcrctof trtnsport merma may include the motor M :intl :i mi.' of sprockets 56- 5S, mounted on Inuit (il) for cngzigpct'torations 52 in tits nliotcwcmxtifc :internals il o prosilc :t driving connection lctv/ccn the motor nl nnd'tl'ic pliotoscnsitivc mntcrinla 3X.

A more folli explained xn tl/tcfttlfovc-tdcnttficri copcncl in.: uppiicnion. thc transportation of tnc pliotmsnvttvc mncnal's 31 behind the cxrowrc ftlzt 32 cltccttvcly acts os n focal plum: chf.: Toc :imc during which :zich point on photowmi c Iinttcriztl: 3l, ta xpod duriniv :i tout! cxpmiirc inicrtztl accords) with tic rclxttonwlttp:

i T =S,'l/

width and 'VL-.velocity :it 'which thc phot@ cmitivt: marc-fiala 3l .crc trrtnsportcd relativ: to thc c1- pofturc slit 32.

lt is cviticnt that y n proficr Selection and correlation of thc rotational rocco of the m of :be worm L'cztrs 43, 55, tito rclzt radii of thc fsprocli t 56, :tn-Ll the 5t :ft 30 upon which tlicy :irc motrntccl, .nd tbc factors-involvcfl-in thc cam clrivc by axial com oithc mirror 33, tbc ra: :it whichtbc object .'9 is canncd by t'nc Scanning m'rtor 32S may be vcry closely chordinzttccl with thc vclocity at which tl'ic photocnsitivc 'tcrials nrc tran pom-cl 'ncnncl tnc cxpoure' slit X lt is noted that a cenrnnnt tot: p rzttc of thc :canning mirror 3l?, assuming :i oonstftnt vclocityof the pitotoz-cn- :itiw: matcrials during exposure, would prodttcc .':n irnza'@ that i5 smeared incr osingly toward t'nc cxtrcmcs of 1li.: cld. This smearing 'of the image is :i rcsult ol' tno incid-.sing cll'cctivc succ-p rate crocs thc Surface ol thc ocowncitiw materials Elli nt increasing oli-:cils ssrn ung'crH A compraba-miic understanding of thc xwci'p vclocity Characteristic of tbc'czlnning mirror 325 which is :Csar-y to vproduce an imago `without smear is not csscntial to the ttndcrstanding; of this invention and, accor gly, an in depth analysis or this problem is not thought tobc appropriate baro. Howe-vcr, it is noted that required sweep rtc a function of the sq'uarc of the cocine of thc instantancous Scan ongle'.

A scanning oxposurc' syst-:m constructed in accordance with tbc teachings o the above-identified copcncling 3pplication may employ a conventional fixed-locus photographic obicctive as the mage-orming`- mcan for tho 's vszcrn; however, for tbc rcasons set forth above, thc iin-xs produced will ar'nibit cylindrical perspective clis-l tortion, detncd above. `En accordance: with tnc principles of invention, means are proidcd for altering the magnification of elemental irna'gcs orrncd socssivcly during tn exposure interval such that all p trts ol thc tomi imag: formed are substantially fren of cylindrical gcrspcctivc distortion.

of :i conventional itnnd-hcld'cztmf- 'ln order that ,th magnification :may lic :t'ltcrqrl object is scanned, in "accordancc, with this invention .optical path lcngth of exposure light in image :mtl

thus thc cicctivo Lnugc distance; is causati to l): vurinf' in a prcdctcrrnincd program during an exposure intcrml.

.it is evident, llowecr, that if such chanlcs optical pain length were cccct' without providing for corrosponding changes in tbc ct't'cctivot'ol distano? of lff: image-forming matins Lltc images formcd by such n scr-113 ning cxposurc system `would cxhibit n incl: of .focus creasing; in magnitude toward the extrem@ of thc tclrl (along the }C--X nazis). Tncrcforc, in accordance miti! anothcr aspect of this invention, maan; :tra orovic'crl for mcans during n. scnno an object in coordination with 'thc said chung in optical path lcnglb of Lb: cxpostttc light.V

FIGUR.. l :.cltcm cally illustrator fttictv rc embodying the ,nrinciplcs of :n: invention rf'niclt muy lso nsccl to conjointlg :tccontpliel: thc :iforclcscrifoccl :hongos in thc optical path length :and cfl'cctivc t'ccrtl dirtnncc. ln .',tccordancf: with this invention, thc lcns 36, in combirzztlion with thc :ipc-muri: stop, is ortiioscopic, acting; lo produc-c un nnngc which is Substantially trcc of Scitlcl clifftortion. Stzttcd in another wily, thc cffcc vc focal distano-,c o tn: lens lf3 for :my gisten object point is n function o the scum! of thu slopc' angle of tlic ojcct chief rzty trom tlm: point. v

in tbc FIGURE-l cmboclimcnt of tti: invention, tlm lcns 26 iS illustrated cl'tcmuticzilly :is :t simple sytnrztctrv C2i! dunlct lcnscomrising :1 ottir o rncnizcu clcmcnte '522i wppotrtcd in :i lcns ltoldcr 70. .fl bcrwccwtlwlcns ments 66 :ind titl. Zi. implc, lwo-clcmcnt lcns litt'J lucen depicted forv thc solo ol'clnrity in f lcccri'oing thc invtrh tion. lt would bc tsnzicrstoocl, howct'cr, that in practico :a more. highly corrected lam may ne prct'crrcd. Tlv; lons. 26 for: e imugcs at :m image arca, defined bcrcin :is 'coing that arca .nt which it is desired to record the imagua, which muy or .may not coincide with or contain tltc loc-'tl :,urfac: in which the bc. imago is form-cd.

ln accordance with this invcntt'on, thc .lens is movocl along thc :mis O`O during exposure to change thc optical path length oftltc exposure light in image: s cctcc., and thus rizc image cliitzincc, lo accomplish the tlcactibcd magnification chung/c.. Sitnttltrtncouly Lhcrcwith, thc lans 2261's pivotal about :1n :tris (labclm L-L in FIGURE l) parallel to thcl` slit 3.7. (und to tltc Y-Y axis) @timing the ctivc slope :mgl: (with respect to thc geometrical axis -i`il ot' lang 26) of clticf rays from socccasirciy Vscanned ject poin' to sary with resulting corresponding vara tions in the ctcctiwc t'oczil distrtncc of tit,- lcns 2".

c'crrtplary structure for effecting such simultfirlcous .slatory :ind rotary movement of lans TAS may inclurlo :i :rit 74 zflixcd to lsns 26 [or rotatably mounting lernt l" 'mw cncls of itfzr't 'ffl crc supportati in slots 76, in a purr of end pl cs, 80, .'32,

liai, arms 85 untxcd to Shaft 7-2 srry pins zl, lo tending into arcuate slotsiy 92, 96 in and plates El), S2, rospcctit'cly,

Lens d: 'ng means are provided for-causing thc plus 33, 9U to periodically trnversc theA blots 92, 9'? to causo the lens 26 to br simultaneously rotated about axslf-L and tmnslatcd along the optical :maisV O-JQ. Such lcnS driving moans are illustratori as comprising a shaft iournalcd in the and plates S0, 82 upon which s mountrrd a pair of radial drivc members 9S, 3*(0 having slots 102, 104 which receive plus 83, Sli), respectively.

The shaft 96 may be driven with the requisite :Killa-- tor] motion by means of a caro 105 on cam shaft 15 ms L-- during :.cpo'sure in accordn with my fica sited program 'und in intimate coordination with tbescztn 5 of the object 1li effected by scanning means 28. lt is' noted that, beuse of the nature of a scanningieective surface, the cumming siu'faces of camsl and S2 are configured such that :he leus Sie is given an angularirate of-rotation which twice'tat ci the scanning cnirror 33.

The manner in which the above-described cleciency scale in the images or' o ifzzis object points is com; pensetes in accordance si-ith thisnvention may 'oe mostv easily understood in connection witha description of thev operation of the total exposure system. it should be noted tbatvin'ordcr to prevent premature exposure of the photosenstivc materials 3i, citkr a capping shutter may b1: employed-or alterneiiiely, the lending edge of theA are; of the photoxnsitive materials 3l to be exposed moy maintained s; ncientiy ozset from the slit 3l to' preclude exposure 'oy stray iight. Prior to the initiation ci :in exposure interval, the angular attitude of cams 52, and 06' :tr: prcxt such that the sor-inning mirror 43S is oriented to scan the object rom right to left (in FiG- URE l) and the pins end 99 are located at corresponding extremes of the arcuate slots ll and 1li-l, respectively. With the pins Eli? positioned-thus. the lcns-to lm distrincc is gt a. maximum. producing the greatest image magnification, and tievmrgular separation, defined by :ingle u, between tb: geometrical :Ulis lli-M and the optical axis O O is also :it a maximum. the lens 36 thereby having t'ne greatest ct'ective focal distance,

Toe operation o the` exposure system is as' follows. Ari exposure interval is ircueted by the cncrgizntion of'drive motor 4, causing the photoscnsitive mnteri'nls 31 to be driven at n predetermined velocity behind the exposure slit 32. Through worm gears d', Si? driving mini CainSZ, the scanning mirror is czioscd to swecpncross the' object to he photographed :xt a sweep `iclocity coordinated with the rate at n'zzicc be photosensitive materials 3i are transported behind me slit 32. The manner in unich the irnrige magnification and the cllcctivc t'oczilv length of the lens is Yvaried during :an exposure interval may be more clearly understood by reference to llGS. 4&4: -which represent zi time sequence of ray diagrams during an exposure interval. FlGS. ia-4c depict the rnzirtncr in which the meg:`4 cation of strip images of successively scanned object stn'psfis varied during; :in exposure interval to produce a total image till parte of which are in focus and substantially free from cylindrical perspective distortion.

As show/nin l'flGQ. l and 4, during the bali' ot an exposure interval :es one h fof the total field, designated 'oy the half-field angl; fz. is scanned, the optical path length in image spese o' the light rom'succcssivcly scanned obi/:Ct areas, and hence the instantaneous ecctive imago distano; is decreased rom a rnriximum to a minimum with a charecteris `c :according with the sccant of the efl'ective instantaneous scan angle. Accordingly, the magnification decreases iront 2 maximum to a minimum value with .a sirnilar characteristic. Simultaneously there' with, the lens 26 is rotated about axis lf'-L to 'etect a decrease in its effective focal distance in n citaructeristie which is also related to the secant of the effective instantaneous scan angie.: v

Similarly, on the oo cosed side of the Z;Z axis, changes in the eteetive focal length of lens 26 and in the image magnification are effected, but wid: au increasing, rather than decreasing, magnitude. The changes in magnification and efective focal length are coordinated in predetermined program, as such that during an expo sure interval z rtota'l image is produced, all parts of which are in focus and Scbstantially free from cylindrical per speetive distortion. l i

The program or characteristic by which the magnilicn- 'tion and effective focal distance are variedduring a scan. of the' object in accordance 'with the invention has been effective 'instantaneousscan'angle As. stated above, the

lin

ya* ecve instantaneous Scan angle .is defined ireln 2 bmg squat :e the ma ons 'oc-Xi component i slope angle (with 'resp-ect to the Z-Z abris) of the rayt in object space from' an object ooint heini' Smici It rollows then, that the explanatorjif mailer above ma he thought ofiin terms of fchiefrays from scanned ot ject .ts and associated slop: anne components., `alhe their in terms of scan angles. c i i egg-e mtodiment of invention been dec-criceti -iructural implementations of Lne invention a' contemplated. In 1:16.15 an embodiment is sho'im r1/helio 4.in a suostantially distortionless, fiat-fieldlerts (showr schematically as a simple mcniscus lens i) is locato; forward' of a scjtnningmirror Z emploved to effec' Satin of the obiect to be photograolzeiTne scarmini rnirror 312 is simultaneously rotatedA and-translated durx lng an exposure inte-wah as shown in the numbered po sinon sequence in FIG. 5, to eliect :1n anculat optica s'cztn ofthe lens M8. As indicated :ih-ove. lens lli! i suostnntxallv free from Seidel distortion and has aAll focal field such that the eective focal distance for given object point is a direct function of the slope anglt of the cl'uet' ray from that point. "illus, by c'octing angular optical' scan of the' lens 119, es Shown the cfectrve focal distance, :it .any instant during exposure will vary :n accordance `with the instantaneous scm nele effected by the cunning mirror l v A 1n order to nccomplisdmalgicarion changes durin'7 a scan of tbc object, in Lize PEG. S embodiment mean; shovrn only schematically at l, may. be provided foiF causing :i gross movement of tbe lcns :ind sfzzmninfy nitrror 11.2 to cflcct changes in the optical' nath lengtii :n mirage spnce. This gross movement of the lens 110 and scanning rnirror Zlby means '1iis closely coordinated with the compotmd movement ot' scinning mirror i12 to produce a simultaneous vnriaion in the erfcctive focal distance and in image magnification in accordance with trie teachingslo this invention'. in Flf`. 5, the mirror S-'l' :ciel the focal plane exposure slit 3?. correspond to minI for S and slit 32 in the llGURE .l structure.

.F.lG. 6 schematically shows still anoticr structure by wnich thc Vinvention may he implemented. The HG. 5 cmbodiment'employs a substantially distortionless flatfielcl lens E16. A scanning mirror i155 is caused to be si multnncjously rotated about :in axis parallel to an exp@ sure slit 32" (corresponding to slit 32 in the FKGURE l embodiment and 32' in the FIG. 5 embodimont) and moved along 2. locus of travel, the configuration of which is effective to produce changes in theoptical path length `of cinosure light in image spacelwnieh have been taught oy tnis invention. Thus, the translator? movement of the mirror 333 effects the rn irisation changes necessary to eliminate Cylindrical ricrspective distortion from the images formed, and the simuitaneoi" scan of the lens H5 by the mirror 18 produces the ci ges in effective toca distance necessary to maintain sharp focus.

lt is noted the time sequence diagrams in FIGS.-

n is rin-rheinod :im :he fried einer (32 in FIGURE -l and 32' in PIG. 5) may ne rotated 9G", or alternatively,

" related in the above explanation to the magnitude of the or may be 'removed entirely, as shovm in FIG. 6, without departing front the principles of this invention..

FIG. 7V shows ya! another embodiment of che invention. A scanning7 mirror 20 mounted for rotation about' fixed' axis is used to scan a flat-field. distoriionless lens E22. Light deflected by the mirror 135 i5 redirected by a second planar mirror 124 to the exposure slit 32". The second mirror i2-4 smoved through a locus of travel (by means not sharm) represented by th: numbered'sequence shown in FIG. to accomplish the changes in optical path length taught by this invention. .Asin the FIGS. 5

and 6 embodiments. the necessary changes in effective im T341 aaa? obicct less angnlarydvergcnt from sait? opsecond moans for cring relat'iwc movement between said imago area and said photosensitivo materials means and said movement-effecting means for ing the optical oath-length of exposure light inv irnage spa, and tizusthe magnification, to vary during a scan of the obcct in a dircct relationship to thc magnitud: of 'tbc scan axis componentot the slope angle in object space ot' uae chief ray from an ob. ,icct point being scannedr thereby to cause thc images formed by said irnage-'onning'lmeans to be substanu'allyv in ocusand substantially frac from cylin- Lirical perspcctivedistortioa; S. A compact photographic camera for exposing pbs insensitive material comprising., n combination:

image-forming means on an optical axis for forming a;

real image of at least a portion or a photographic object at a predetermined imagc arca; iight reflective means for folding said optical axis I'rotn said object to said. image arca; scanning means disposed on' said optical axis for cooperation with :aid imagcorming means to cfiect a continuous angular optical scan of thc object such that successively scanned obj-:ct points are imaged in succession at said image;

means for effecting relative movement between said- Vimage area and said photoscnsftive material al a predetermined velocity coordinated with the scan ofl saidscanning means such tiia adjacent' object points scanned successively are imaged in succession upon said photoscnsitiv: material during said relative movement, whereby an imag: of the object may be recorded upon tnc photosf: s itivemalcrial; and

compensation means coordin Led' with said scanning means and said movement-ei acting means for causing the optical path length oi exposure light oetwccn the last surface of said image forming means and said image arm in a direct relationship to the magnitude of the scan anis component of the slope angle in object space o the chiefray from an object point being scanned to substantially reduce cylindrical perspectivc ostortion in the images formed by said im age-forming means.

A photographic camera including a scanning capo# l sur@ sysusrn for exposing p'ootoscnsitiv'ematcrial in the camera, comprising:

image-forming means on a: optical axis for forming a cal image of at a portion of a photographic ol ject at a predetermined image area; mcans dcriningan elongacd focal plane-aperture :1t said image arca; i scanning means disposed on said optical axis for cooperation with saiti image-forming means to a continuous angular optical scan o the object during an Aexposure inwrv'al sucia that succcssyely object points are imaged in succession by said image forming means at said image arca;

transport'rncaus for tzansporing photosensitive mato rials behind aperture through said image area at a predetermined velocity coordinated with .the scan rate of said scanning means such that ad ia cent object points scanned successively arc imaged in succession upon said pbotoscnsitive materials during transportation thereof behind said 'aperture to maintain said image of the object stationary relative to said pnoiosansifive materials; and i compcnsation means coordinated with said scanning image-forming tncanson an optical axis for ionizing'v a rcal image of at least a portion of a photographic object at a predeterminati image arca, said imagefor'ming means having a geometrical axis and an c'icctive focal ,distance for any given object 'point which isa direct function of the slope angle with respect to said geometrical artis of the chier' ray from that o'bjoct v means dcfini'ng an elongated focal plane aperture at said image arca;

scanning mca'ns including saidimagc-forming means fot' crccting an angular optical scan of the object in co vordination with an' angular optical scan of said image;- iorming means by chicf rays from successively scanned. object points to cause object points near an angular cxtremebf the iicld o saidimage-iorming mcansto be imaged at greater focal distances than objectpoinls less angularly divergent from said optical axis;

ransport means for transporting photosensitive matcrials behind said aperture and through said image areaal n prcdctcrrnined velocity coordinated with this scan rate of said warming means such that adjacent object points scanncdsucccssively are imaged successiycly upon said photoscnsitivc materials during4 transportation thereof bchind said aperture to main-I tain said image of the object stationary relative to said p hotosenstivc materials; and compensation means coordinatgd. with said .scanning means and said transport means for causing the optical path length of exposure light in image space and thus the magnification, to vary during a scan of the object in a direct relationship to the magnitude of Los scan axis component of the slope angle in object space of the chief ray from an object point losing scanned to cause the images immer! by said image-forming.

means to be substantially in focus and substantially free from cylindrical perspective distortion. 8. The apparatus defined by claim I wherein saidscznning means includes alight reflective scanning surt'amounted t'or angularmovc'mcnt behind said image-forming means iorcfecting a scan ot' thc obiect through said imagoorming means 9. ,The apparatus clencd by claim svhcrein said means for varying said optical path lcngth includes `means for ciiecting a gross displacement of said image-forming means with 'respect to said image arca during a scan of thc object. i

i9. The apparatus dao-cd' 'oyclaim S, "wherein said means for varying `said optical path length comprises iight reflective means in tbe light patin between said imageforming means and said image'area and motive means or translating said .light rcficctivc means during a scan of the object along a locus-of travel effective to cause said variations in 'optical path length.

il. The apparatus defined by claim 1Q wherein said light reflective means and said scanning means include it single light rctectivc surface.

12. The apparatus defined by claim-1l) wherein sairlligh.- i

sbt reflective surface ciclos reilectiye means includes a li sive osaid Scanning Sudam. A

l. Tile apparatus defined by claim 7 wherein ing angfnar movement o said image-forming means dui'- ing :mn ofV the object :about an psxmell in said axis of anguar movement of said scanning surface zo. aampgh said angular aplica scam of said image-form mg mans:

353-. 'Das appvgraus demed in lsm wherein said 10 .DA'xf-ID B. WEE-BEER, Assstam means for varying said optical' 'palb Icngh includes mnsu br ewng a gross dspnccmcnt of sad magbformng means with respect osad image :arcathrough a prcdr mined Ecus of Havel during a scan @i Lb@ obj-:5L

Saris :mix

3,136,751 1,950,156 2,632, i9@ smsasm 3,057,259

INJED "ffl/1935 OHN M. ECRAN, Primary Examiner 

